High Speed 1541 Disk Operation
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High Speed 1541 Disk Operation We can still recall our first experi ing about for a usable disk copy pro While all these fixes addressed many ence with the 1541 disk drive. Actually gram. Those early programs took from aspects of the problem, they still did it was a 1540 disk drive that we were 30 to 40 minutes to back up an entire not resolve the basic issue. The 1541's running off a VIC 20 back in 1983. We disk. The initial improvements consis serial bus is essentially slow. Although had paid over S400 for it; in view of ted of a reduction in the number of disk fast loaders did alleviate the tedium for that princely sum, we were understand swaps needed to copy a disk with a sin some applications, most "serious" us ably disappointed when we found out gle drive from six to five and finally ers of the C-64 obtained very little that the 1540 was not completely com down to just three. benefit. Operations involving data files patible with the C-64 (but that's another Condilions pretty well stabilized for for word processors, spreadsheets and s(ory). It wasn't long after the luxury about a year until a young man in Ger databases were still slow. In particu of not using cassette tapes wore off that many discovered a high speed serial lar the saving or writing of data re we realized that the 1540/1 was not the bus technique and the era of three min mained a time-consuming process. speed demon we had hoped it would ute copiers was upon us. These were This month we examine four prod be. In fact when applied to the much shortly followed by a variety of fast ucts which accelerate disk drive per larger programs of the C-64, ihe 1541 loaders, some in cartridge form and formance, three of which attack the was downright tedious. others on disk. Software publishers problem of the serial bus direcdy. They Nevertheless, those were still the latched on to the idea, and very soon do this using the most direct method days of wonder and the discovery of mosl games had a built-in fast loader possible, entirely bypassing the serial just what our machines could do. It of some kind. In the end even Com bus. If you can handle the required wasn't long before we actually filled our modore saw the light and pretty much hardware hack, one of these products first box of 10 disks (at $3 to $4 dol corrected the problem with the C-128 may be the best investment you can lars per disk, no less) and started east and the 1571 disk drive. make for your C-64 and 1541. DOLPHIN DOS Micro Accessories of S. A. TOP. Dol Commodore 64 and 128 phin DOS We first encountered Dolphin DOS shown in at the Summer 1987 MARCA conven stalled in the tion. At that time Mark Grove of 1541. The Grapevine Data Products was doing 6502 micro some pretty impressive things with a processor C-64 and a 1541 which had Dolphin and 6522 DOS installed. In the course of a few VIA are from minutes we watched Mr. Grove load your drive; and run a selection of C-64 programs the addition at seemingly instantaneous speeds. As al RAM is at it turned out the load times were not the bottom instantaneous; however, we were able with the to count the seconds they took on the ROM directly fingers of one hand. This was with pro above it. grams which we knew would lake 1 I _ much longer to load under normal cir -"It BOTTOM: >- r • ' cumstances. «f. *■ *■* ■ -ill Dolphin VJi" rsi—Sn»*R "j, We subsequently found out that Dol . •: : -f .-=— ^ ' ''"■'Jl.1 DOS replace . HI phin DOS came from that land down : I i '.^"^USlT. ment Kernel below, South Australia to be precise, -Nil : \ i*. with its con ■ and that it was not available in the U.S. trol switch as :Mi O al that lime. Since Micro Accessories installed in ■ ■ I; ;* of S.A. has expressed an interest in the '■• ."^ - —- •- '.*■ the C-64. -, - <*■'■. U.S. market, we have decided to pre ' - sent a review of this product. We feel READER i ' SERVICE JJSM that the encouragement of development mm.; F :/;■■' | r . S 1111 NO. 231 along these lines will benefit the Com- AHOY! 57 modore community. Unfortunately, the affecting the contents of memory, load Control Key distribution details for Dolphin DOS Commands ing, running, saving and listing pro were still not available as we went to grams to both the screen and the print CTRL B Cursor to bottom of screen press. er, and quick access to the built-in CTRLG Cursor 20 columns right Dolphin DOS is a combination of memory monitor and its associated data CTRL L Delete to left of cursor hardware and firmware which equips .scroll functions. CTRL K Delete to right of cursor a C-64 and a 1541 disk drive with a Operation of the full screen editor CTRL @ Drive status full 8 bit, high speed parallel interface. has been enhanced with the inclusion CTRLD Display directory When Dolphin DOS is installed it en of control key commands. These are CTRL A Key repeat toggle dows the computer and disk drive with CTRL ' Copy screen to printer listed in the table at left. Note the use the ability to load 100 block program CTRLV Reset video display of the Commodore key for the last files in under three seconds. The save CTRLX Disable function keys command. time for this size file clocks in at un CTRL & Enable function keys As mentioned above. Dolphin DOS der seven seconds. These figures rep CTRL DEL Copy text to buffer and is provided with a built-in memory resent speed improvements, as com delete from screen monitor. This is minimal monitor im pared to the unadorned hardware, of C=OEL Retrieve text from buffer plementation, as it lacks the ability to 20 and 10 times respectively. The read assemble or disassemble 6502 code. ing and writing of sequential files is locking and unlocking of files, there The monitor does provide the capabil improved by a factor of 10 times. The by protecting them from inadvertent ity of displaying and modifying the manipulation of relative files shows the erasure. In addition the disk drive it contents of memory in cither hex or least benefit, with an improvement of self acquires the option to read and ASCII. Instead of scrolling the screen only a factor of three. In exchange the write out (o track 40. This increases in the usual manner, blocks of data may C-64 loses the ability to access the cas the disk storage capacity by 85 blocks be paged forward or backward. sette recorder, which we feel is a rea or 21 kilobytes. As an added bonus, the If the computer is fitted with a reset sonable compromise. alleged save with replace bug has sup button, then a RESET/SPACE will In addition to the raw speed enhance posedly been fixed. autostart a program in the $8000 block. ment, Dolphin DOS provides some im The function keys take on new mean BASIC programs can be retained in provements to the operating environ ing with Dolphin DOS, 12 meanings memory with a RESET/RUN STOP ment. To start with, the LOAD com to be exact. The extra four meanings combination. A RESET/1 will fill mand defaults to the disk drive as de are accessed by pressing the Commo memory with zeroes, while a RESET/ vice number 8. Access to the disk com dore key along with a function key. The CTRL jumps into the monitor. mands is simplified by a full-featured function keys issue frequently used The manual also indicates that a DOS wedge. The disk drive's command commands which involve the disk Centronics printer connected to the us repertoire is extended to include the drive, displaying the directory without er port is directly supported as device number 4. We did not verify this, as TOP: the Dolphin DOS user port connector RapiDOS is not provided with a pass through, components although one is supposedly available. in the 1541. With regard to compatibility with Clockwise commercial software, Dolphin DOS from top performed very well. Most of the pro [eft: circuit grams we tried worked without any board with problems. If compatibility problems do new 6522 occur, then Dolphin DOS may be man VIA, cable ually disconnected in stages as re to user quired. The built-in soft switches can port, main be used to cut out the fast load, dese circuit lect the extra RAM in the disk drive, board. and deselect the parallel bus. As a last BOTTOM: resort you can electrically switch off In the 64: Dolphin DOS entirely via separate tog Kernal gle switches on the computer and the ROM on disk drive. left, user Dolphin DOS requires installation in port adapter both the disk drive and the computer. with control The disk drive hardware can be in switch to stalled only on the short board version right. of me 1541 disk drive. If you have one READER of the original long board versions of SERVICE NO. 232 the 1541, or a 1541C, then Dolphin DOS is not for you. To start with, you open 60 AHOY! REVIEWS up your disk drive and remove ihe in 1541 disk drive, take a close look at switching between drives 8 and 9, and ternal radio frequency shield.